This study proposes to examine the adaptive responses of Cortical bone to applied mechanical stress. Its overall objective is to attempt to quantitate the remodeling responses of bone to graduated loads. Experimental models will be examined which will create stress fields that are essentially simple compression, simple tension, and the stress fields accompanying bending moments. These stress fields will be created by static loads in initial studies. Analysis of remodeling will be by gross morphology, radiological, and quantitative histology. Stresses will be evaluated by strain gage measurement and by theoretical stress analysis (by finite element techniques where necessary) and will be correlated with the measured changes. The research will attempt to identify the components of stress associated with bone formation and resorption. The goal is to develop predictive models for bone remodeling in critical loading situations both within and outside normal physiologic ranges.